Metal container having a solderless side seam



SePt- 5A, 1939- w. G. PLUME Erm. 2,171,711

METAL CONTAINER HAVING A SOLDBRLESS SIDE SEAM Filed June 27, 195sPatented Sept. 5, 1939 METAL CONTAINER HAVmG A SOLDER- LESS SIDE SEAMWalter G. Plumb, Glen Roch-N. J., and Herbert Schrader, Wheeling, W.va., 4assignors to Continental Can Company, Inc.,- New York, N. Y., a.corporation of New York Application June 2v, 193s, serial No. 87,774 1cmm, '(01. zzo- 181) 'I'he invention relates to new and usefulimprovements in a sheet metal container having a body portion formedfrom a blank, the side edges of which are joined by a side seam.

f, An object of the invention is to provide a container of the abovetype wherein the side seam is made Huid-tight by the insertion of anonmetallic packing material which extends throughout the entire lengthof the side seam.

1., A further object'of the invention is to provide a container of theabove type wherein the body `wall is shaped atboth sides of interlockingportions ofthe side seam so as to prevent any lateral movement of thehooks due to collapsing stresses 1:1 placed upon the outer face of thecontainer body.

A still further object of the invention is to provide a container of theabove type whereinrthe packing material is in the form of a s'tripsecured to the body blank by cementing so that when the vr hooks areformed, said strip will lie within the inner hook and contact with theinner and oute faces of the outer hook. A still further object of theinvention is to provide a container of the above type wherein lthepacking strip is cemented to the body' blank in the region from whichYthe inner hookl and inner lap portions are formed and prior to, duringor after the notching of the blank and the bending of the same to formthe hook. Y These and other object will in part be obvious and will behereinafter more fully described.

In the drawing which shows by way of illustration one embodiment oi theinvention- Figure 1 is a fragmentary plan view of a portion of the bodyblank from which the inner hook and the inner lap portions are to beformed with a packing strip applied to the body blank; 2 is aviewsimilar to Fig. 1, but showing the body blank at both side edges thereofslit and 40 notched preparatory to the forming of the hooks;

Fig. 3 is a view similar to Fig. 2, but showing the body blank bent toform the hooks; Y Fig. 4 is a sectional view through the side seamtransversely thereof and prior to the submitting of the body to abumping action for completing the side seam;

Fig."5 is a sectional view on the line 5 5 of Fig. 7; Fig. 6 is asectional view on the line E-G of 5@ Fig. 7, and

Fig. 7 is a side elevation of a container embodying the improvements.

Many eorts have been made to produce a sheet metal can body wherein theside seam is made liquid-tight without theuse of a solder bond.

Y bent to form the outer hook I3.

Such efforts have not been successful. One of the diftlculties has beento produce a side seam which would be liquid-tight inthe region wherethe lock portions join the lap portions. It is believed that applicantshave overcome this diilicuty by utiliz-- 5 ing a packing materialpreferably in the form of a strip or gasket which extends throughout theentireregion of the side seam. This packing strip or gasket ispreferably made of paper, which paper may or .may not be saturated witha seall0 ing composition such as is commonly used in the forming of.hermetic joints in interlocked metal parts. The preferred form of seamused in the joining of the side edges of the body blank is a lock andlap seam. 'I'he packing strip or gasket l5 is preferably attachedto thebody blank before the blank is notched and the hooks formed therein. Ithas been found that when a single packing strip is secured to the bodyblank so that it will extend throughout the entire length of the m sideseam including thel lap portions, a very efficient liquid-tight joint isproduced.

It is believed that the invention will be better understood by a moredetailed description of the illustrated form thereof, as shown in thedraw- 25 ing. The body blank which is shaped into the container body isindicated at B. A pre-formed packing strip or gasket S preferably ofpaper is secured to the body blank along the side edge thereof. Thisstrip is of a width vsubstantially 30 equal to twice the lengthof theinner hook? After the strip has been secured to the body blank, then thebody blank is subjected to the usual slitting and notching devices sothat slits I0 are formed in the body blank and in the packing strip and35 notches II are formed at the other side edge of the body blank. Thebody blank is then presented to the usual devices for forming the hooksand the metal between the notches Ill, I0 is folded back to form thehook I2. inasmuch as the n packing strip S is substantially twice thewidth of the inner hook, the packing strip will extend across the innerface of the inner hoo.; and along the outer face of the body wall to theextent of the overlap of the in ne hook. At the same time 45 that thehook i2 is formed, the body blank is It will be noted that the packingstrip orgasvfket not only lines the inner face of the inner hookbut,also extends across and covers the lap porn tions I4, Il. After thehooks are formed, the

blank is shaped into body form and the hooks interlocked as indicated inFig. 4. The interlocked hooks and body are then subjected to a bumpingaction which completes the formation of sa the side seam. During thisbumping action, the body wall is sharply bent so that it lies close tothe base of the inner hook I2. This is indicated at I5 in Fig. 5 of thedrawing. The body will is also bent outwardly and shaped as indicated atII in Fig. 5. This portion I6 lies close to theA base of theouter hookI3. The purpose of these sharply bent portions at each side of the sideseam is to hold the interlocked hooks in engagement with each other.AAny internal pressure created on the can wall tends to draw the hookstogether. Any external pressure on the body wall in the region of theside seam tends to unlock the hooks by collapsing the body wall andshortening the circumferential extent thereof. When the hooks are solderbonded, the hooks cannot be interlocked without shearing the solderbond. When, however, a packing strip o'r gasket is used, some mechanicalmeans is necessary to prevent this engagement of the hooks or anymovement of one hook relative to the other which is likely to produce aleak. The shaping of the side seam, as above noted, prevents any lateralmovement of the hooks relative to each other which would disengage the-hooks sufficiently to cause a leak.

Furthermore, when the wall of the container body adjacentthe side seamis shaped so as .to provide a rib extending along the base'of the outerhook, this rib becomes a girder which operates to-strengthen the seamand prevent any bending of the' body wall from shocks or blows againstthe outer surface thereof. When the side seam is strengthened by thisgirder and the hooks positively held interlocked, then `the containercan be placed under vacuum and the differential pressure on the sideseam will not cause any bending or bowing of the side seam withresulting leaks. When the side seam is bumped and the hook portionsbrought into firm contact with the packing strip or gasket S, the lapportions I4 are also caused to firmly contact `with the packing strip.After the can body has been formed, it is anged and then the bottom endE is secured thereto by double seaming in the ordinary manner. Theentire lap portions are rolled into the side seam and this will bind thelap portions against the packing so firmly that a liquid-tight joint isobtained at the juncture between the lock portions of the side seam andthe lap portions of the side seam. After the container is iilled, thenthe top end E' is secured by double seaming and this likewise produces aliquid-tight joint at the junc. ture between the upper end of the lockportions of the side seam and the adjacent lap portions of the sideseam.

The paper packing strip or gasket without any special treatment, whenextended throughout the entire length of the side seam including the lapportions, will produce a liquid-tight joint. It is, however, foundpreferable to saturate the paper either before or after it is applied,with a sealing material such as is used in the forming of hermeticjoints at the double seams. It is preferable to secure the packing stripto the metal blank which is to form the body by cementing the strip tothe blank prior to the forming of the hook and the lap portions, for inthis manner the packing strip can be placed quickly and accurately sothat it extends throughout the entire length of the side seam and is sodisposed relative to the interlocking and lapping portions as to producea fluid-tight joint. While it is preferred to apply the packing in theform of a strip, it will be understood that it may be otherwise applied,but it is essential that there shall be a portion of the` packing stripor gasket extending throughout the entire length ofthe side seamincluding the interlocking hooks and the lapping portions at the endthereof. In fact, in the nished container, this packing strip not onlyextends throughout the entire length of the side seam but into thedouble seam so as to insure a liquid-tight joint in the region where.

in the side seam merges into the double seams.

When the container is provided with a liquidtight side seam such asdescribed above and without the use of solder, the body may be i'ormedVfrom black sheet metal or any other type of metal winch it is diiilcultto solder. Furthermore, when a liquid-tight joint is produced withoutthe aid of heat, then the body blank can be decorated all the way up tothe side seam hooks and thus a continuous peripheral decorationobtained. It is further obvious that when the side seam-is madeliquid-tight without the use of solder, the container can be fabricatedat a less expense. A

l It is obvious that other forms of side seams may be used for joiningthe edges of the body blank, and other types of notches may be used inconnection with a lock and lap seam. It is essential, however, that thepacking material shall extend throughout the entire limits of the sideseam and into the end seams joining the ends to the can body.

Having thus described the invention, what we claim as new and desire tosecure by Letters Patent is- A sheet metal container comprising a 'bodyportion having its edges joined by a side seam including oppositelydisposed interlocking hooks, lap portions at the ends of the side seam,closure ends seamed to said body portion, a paper gasket.

saturated with a sealing composition disposed between the adjacent facesof the ,hooks and extending as a continuous packing strip between thelap sections and into the double seam joining the closure ends .to thebody portion, said body being shaped at each side of the side seam.

so as to hold said hooks firmly interlocked when subjected to stress onthe exterior of the con-

